Portable hand-operated point drivers for use by glaziers in assemblying glass in a window sash are generally trigger operated for forcibly driving the lowermost point in a stack of points provided in a magazine, and U.S. Pat. No. 1,744,700 shows the typical construction of present day point drivers. The magazine comprises an elongated receptacle for the stack of points, and a spring biased follower or bail urges the stack of points downwardly. The spring force exerted by the follower can be overcome to permit removal of the follower for reloading the magazine, but the magazine is generally so constructed as to receive only one particular size point.
A trigger mechanism is provided for operating a push plate, and includes a coiled compression spring, and a trigger return spring, and the trigger or handle comprises a bell crank which retracts, or cocks the push plate, such that when the compression spring reaches a predetermined position a predetermined spring force urges the lowermost point in the stack into the wood sash. Since points of only one predetermined size can be loaded in a particular point driver, the displacement and consequently the spring force provided by the compression spring, need readjustment only very infrequently. Once set up for driving a particular size point there is little need to alter this adjustment in prior art point drivers.